The present invention relates generally to pointing devices and, more particularly, to a pointing device having a force feedback mechanism including a gimbal mount that provides improved coupling with the user manipulable object to produce increased accuracy and improved game play.
One type of pointing devices incorporates a force feedback feature. Such devices are commonly used in an interactive system which typically displays a visual environment to a user on a display screen. The user can interact with the displayed environment to play a game through the use of a user manipulable object or user interface device, such as a joystick, joypad button controller, mouse, trackball, stylus and tablet, or the like. The interface device is connected to the computer system controlling the displayed environment. The computer updates the simulation or game in response to the user""s manipulation of the user manipulable object, and provides feedback to the user. Some interface devices produce tactile or force feedback to the user by providing physical sensations to the user. Typically, motors or other actuators are coupled to the user manipulable object and are controlled by the computer system. Position sensors monitor the position of the user manipulable object and provide the measurement data to the computer system, which processes the data. Based on the data, the computer system generates control signals for controlling the motors to produce feedback forces to the user manipulable object, thereby conveying physical sensations in addition to visual stimulation to the user.
Pointing devices such as joystick devices tend to have extensive linkages that include, for example, gimbals or other mounting components. Position measuring sensors are typically placed remotely from the user manipulable object such as a joystick handle where the movement is occurring. As a result, tolerances between the linkage components (for instance, the various parts of the gimbals and mounting structure for the sensors) reduce the precision of the position measuring system. This in turn diminishes the quality of the game play.
The present invention is directed to a pointing device such as a joystick including an improved force feedback mechanism which has improved accuracy and provides better game play. The mechanism employs a pair of gimbal arms. One of the arms is a double sided or forked gimbal arm which provides a better coupling between the joystick and the force feedback mechanism to reduce backlash and provide improved game play.
The pointing device includes a position sensing apparatus for a user manipulable object such as a joystick. The position sensing apparatus desirably employs sensors that are directly or essentially directly connected to the user manipulable object to reduce backlash, and are mounted in a way to substantially eliminate off-axis loading on the sensors. The reduction of backlash produces more accurate position measurements to enhance game play, while the elimination of off-axis loading protects the sensors from damage to the internal mechanism thereof.
In some embodiments, the pointing device incorporates a force feedback mechanism which includes a gear reduction system that utilizes an annular reduction gear portion for force transmission from the force feedback actuator to the user manipulable object of the pointing device. The annular reduction gear portion produces a greater gear reduction than a conventional gear in a given space and hence a smaller actuator can be used. The gear reduction system is configured to take up less space. As a result, the pointing device is compact and accurate, and can be produced economically.
In accordance with an aspect of the present invention, a pointing device comprises a joystick and a first gimbal arm. The first gimbal arm includes a first arm portion and a second arm portion which are connected to the joystick to permit rotation between the joystick and the first gimbal arm around a first axis. The first and second arm portions are disposed on opposite sides of the joystick. A second gimbal arm is connected to the joystick to permit rotation between the joystick and the second gimbal arm around a second axis.
In some embodiments, the joystick includes a first circular protrusion and a second circular protrusion disposed on opposites sides of the joystick and oriented along the first axis. The first gimbal arm includes a first circular aperture in the first arm portion for receiving the first circular protrusion and a second circular aperture in the second arm portion for receiving the second circular protrusion.
In some embodiments, an actuator is coupled with the first gimbal arm for driving the first gimbal arm and the joystick in rotation around the second axis. A gear system is coupled between the actuator and the first gimbal arm, and provides a gear reduction from the actuator to the first gimbal arm. The gear system includes at least one annular gear portion which includes teeth on a concave side engaging teeth of a pinion for driving the annular gear portion.
In some embodiments, a first sensor has a first sensor body coupled with a first sensor shaft. The first sensor shaft is substantially immovably connected to the joystick to move with the joystick. The first sensor shaft is rotatable relative to the first sensor body generally around the first axis. A first mounting mechanism is provided on the first gimbal arm and is coupled to the first sensor body to permit the first sensor body to move with the first sensor shaft except in rotation around the first axis.